Railway traffic controlling apparatus



Nov. 10, 1942. v LEWIS 2,301,297

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Jan. 25, 1939 10 Sheets-Sheet l Bq A MW as a Kl 141m: 5

4118 H- pm 4%?! 11255 IBNES k A155 166 m 29" IN VENTOR Lloyd ewz's.

I115 ATTORNEY Nov. 10, 1942. v v. LEWIS 2,301,297

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Jah. 25,-1939 l0 Sheets-Sheet 2 f 13 PBNE P5;

IOXS PAWS IOQGP INVENTOR Lloyd ewc's.

H13 ATTORNEY Nov. 10, 1942. L. v. LEWIS 2,301,297

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Jan. 25, 1939 10' Sheets-Sheet s U U Y 512E 52W 0 1 r W 7AM ZANWS 10;; C

21112 811R 101m 276 ZANES jANW 1m axs WWW: mar mm; mm eao *U-- o mm U' I 277 11w 1mm 278 JIZE'S 352W 518W C A Fig 1D.

3 INVENTOR:

Lloyd ewzs.

117.5 ATTORNEY Nov. 10, 1942. L. v. LEWIS 230 291 RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Jan. 25, 1939 10 Sheets-Sheet 7 nfig 2G 24S 21113 1L8 2H2 5W3 5 3-1 I B W C V j' ibf zm 52R 5W1 .ZWP 15 186R Q mg INVENTOR Lloyd L'ewzls.

BY L

H115 ATTORNEY Nov. 10, 1942. 1.. v. L EWIS 2,301,297 RAILWAY TRAFFIC CONTROLLING APPARATUS I Q v Filed Jan. 25, 1939 1Q Sheets-Sheet 9 INVENTOR v 2 ligyd VZL'ewzs.

HIS ATTORNEY Patented Nov. 10, 1942 RAILWAY TRAFFIC CONTROLLING APPARATUS Lloyd V. Lewis, Pittsburgh, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application January 25, 1939, Serial No. 252,803

56 Claims.

My invention relates to railway tralfic controlling apparatus for governing the movement of trafiic through a track layout comprising a plurality of track sections interconnected by track switches which may be variously arranged to form dilferent trafiic'routes. More particularly, my invention relates to an interlocking control system having an illuminated diagram of the track layout in the signal cabin or other point of control, provided with push buttons or the like at locations corresponding to signal locations on the diagram, for controlling the track switches and signals to permit train movements over the several routes.

One object of my invention is the provision of an improved arrangement of circuits for seelct-. ing each route inresponse to the successive operation of the control buttons for the two ends of the route, which arrangement is particularly adapted to the control of large and complicated track layouts.

Another object of my invention is the provision of improved means for operating the switches by individual levers when desired, together with means for indicating suchoperation by distinctively illuminating corresponding portions of the track diagram.

A further object of my invention is the provision of means for operating a call-on signal or the like in response to the operation of only the button at the entrance to the route which such signal governs and without the use of an auxiliary button as heretofore used. Other objects, purposes and features'of my invention will be pointed out as the description proceeds.

My invention is an improvement upon those disclosed in the copending applications, Serial No. 14,868, for Interlocking control apparatus, filed April 5, 1935, by Earl M. Allen and Howard A. Thompson, Serial No. 118,609, for Railway tramc controlling apparatus, filed December 31, 1936, by John M. Pelikan, Serial No. 196,435, for Railway traffic controlling apparatus, filed March 17, 1938, by Ronald A, McCann, and Serial No. 224,165, for Railway trafiic controlling apparatus, filed August 10, 1938, by Henry S. Young.

I shall describe two forms of apparatus embodying my invention and one modification thereof, and shall then point out the novel features thereof in claims.

Referring to the accompanying drawings, Figs. 1A to 1H, inclusive, taken together illustrate diagrammatically the circuits for a route interlocking system embodying the first form of my invention. A plan of the track layout which I have" 55 chosen to illustrate my invention is shown inthe upper portion of Fig. 1F, and a suitable control panel containing a track diagram constituting a miniature representation of this track layout is shown in the upper portion of Fig. 1G. Figs. 2A to 2E, together with Figs. 1F, 1G and. 1H, illustrate the circuits and apparatus for the second form of my invention.

Fig. 3 illustrates an auxiliary system of signal control which may be used with either form of my invention by superimposing these circuits upon those of Fig. 1D or Fig. 2D.

Considering the drawings for the first form of my invention in detail, Figs. 1A and 1B show the primary route selecting circuits and relays controlled directly by the push buttons P of the control panel of Fig, 1G. Figs. 10 and 1D show the circuits for switch control relays W'R andsignal control relays HR, respectively, which relays, are

governed by the relays of Figs. 1A and 13.

Fig. 1E shows the circuits for a series of white lamps for at times illuminating the-tracks of the operators track diagram of Fig. 1G.

Fig. 1F shows the track relays TR for the various sections of the track layout, a switch indication relay WP with typical circuits for the repeating relays it controls, two types of circuits for the approach locking relays AS employed in the system of my invention, and the circuits for section locking relays ES and WS.

Fig. 1G contains the circuits for a series of red lamps for attimes illuminating the tracks of the operators track diagram shown therein, and also shows the circuits for red and green lamps for the signal indicators GK located in the push buttons P of the diagram. Fig. 1G also shows, in the lower portion of the operators panel, a series of switch levers W by means of which the switches may be operated individually, or optional routes may be selected manually. The circuits controlled by the levers W are shown inFigs. 1A, 1B, 1C and IE. I I V Fig. 1H shows a signal circuit networkforjenergizing the mechanism G for the signalsand also shows the signal indication relays RGP.

Figs. 2A to 2E, inclusive, illustrate modifications of the corresponding views of Figs. -1A to.

IE, respectively, as employed in the second form of my invention, both forms employing thesame drawings Figs. 1F, 1G and 1H, as already mentioned.

Fig. 3 shows an auxiliary control system in which the buttons P may be used to control the signals individually, without operating the'route selecting apparatus, when aroute has been established by the operation of the individual switch levers W.

Similar reference characters refer to similar parts in each of the several views.

In order to simplify the description, I shall first explain the functions of the several parts of the first form of my apparatus, and shall then describe its operation in detail, after which I shall point out the distinguishing features of the second form and shall describe the operation of the auxiliary apparatus of Fig. 3.

Referring first to Fig. IF, it will be seen that the track plan as shown represents two parallel main tracks interconnected by crossovers I, 5

and I, the lower track being connected to a siding by a single switch 3. For simplicity each pair of track rails is represented by a single line in the plan. While a specific track layout is disclosed, it is to be understood that the apparatus is adapted to control any track layout encountered in practice, including layouts that may involve entirely different combinations of switches and signals, the present layout having been chosen to illustrate the principles of my invention in a simple manner. As indicated in the drawing, the tracks are divided into sections by insulated joints, the detector sections of the upper track which include the track switches being designated 'by the references IT and 5T, while those of the lower track bear the references 4T, ST and IT. It is to be understood that each track section is provided with the usual closed track circuit including a track battery B and a normally energized track relay, each track relay being identified by the reference TR with a numerical prefix identifying the track section to which it corresponds, as illustrated, for example, by the relay ITR for section 1T. Each detector section track relay such as relay ITR controls a slowpick-up, slow-release repeating relay, such as relay lTP, having a circuit extending from one terminal B of a suitable local source of current over the front contact of the track relay, through the winding of the repeating relay to the other terminal C of the same source.

Each track switch of the layout is actuated by a power-operated switch machine SM, as illustrated for switches IA and 1B, which may be understood to be of the type shown in the Zabel Patents Nos. 1,293,290 and 1,413,820. Each switch machine is provided with the usual motor having its operating circuits controlled by the contacts of a polarized switch control relay WR in the manner illustrated in the Willard Patent No. 1,380,452, as indicated diagrammatically for relay 'IWR by dotted line connection in the drawing, and it is to be understood that each switch or pair of switches will be operated to normal, as shown, or to reverse, when the control relay WR is energized and its polar contacts are closed to the left or right, respectively. Each relay WR is controlled in the manner illustrated in Fig. 20, as hereinafter pointed out.

Each switch machine is provided with the usual switch circuit controller as disclosed in the Zabel patents hereinbefore referred to, for controlling a polarized switch indication relay such as the relay IWP. For an understanding of the present invention it will suffice to point out that when both switch machines 1ASM and lB--SM of the crossover I are locked normal or reverse, the corresponding relay TWP will be energized and its polar contacts closed to the left or right, respectively. It is also to be understood that relays similarly controlled by the switch machines for the crossovers l and 5 and the single switch 3.

Each switch indication relay WP controls a pair of switch correspondence relays such as the relays INWC and IRWC, each of which is energized only when the polarized relay WP is energized in a position corresponding to that of the associated switch control relay WR'.

Signals 4A and 10A are high speed signals governing main line train movements and each is provided with a distant signal l9 or 2%. Each of the signals 2, 4C, 6, 8, I00 and i2 is a slow speed signal, while signals 40 and I00 also serve as call-on signals to admit a train to an occupied block, being controlled for this purpose by the manually governed call-on .stick relays ACOS and IUCOS shown in Figs. 1A and 1B, respectively.

The signals may be of any desired type, but as herein illustrated, it is to be understood that they are of the well-known searchlight type having a mechanism G of the form disclosed in the E. J. Blake Reissue Patent No. 14,940, of August 31, 1920, which mechanisms are controlled in the manner shown in Fig. 1H. Each signal is provided with the usual back lock or signal indication relay RGP, as shown, which relay is energized only when the corresponding signal indicates stop. Each relay RGP controls an approach locking relay AS of corresponding number such as the relay 4A8 or ZAS of Fig. 1F, and

IWP, 5WP and 3WP, shown in Figure 11-1, are

also controls the lamps of the associated signal indicator GK of Fig. 16.

Each slow speed signal is arranged to indicate either clear or stop. A distant relay DR, controlled by the next signal in advance, controls the polarity of the current supplied to the mechanism G for each high speed signal 4A or [0A to provide a third, or caution indication. The circuits for relays D are omitted since they form no part of the present invention and suitable circuits are well known.

The manual control of the signal mechanisms G by the route buttons is effected by means of the signal control relays HR shown in Fig. 1D. Each signal control relay HR and the back lock relay for the signal it controls governs the approach locking relay AS for that signal. For each slow speed signal the locking relay is controlled like relay ZAS in Fig. 1F, which relay is released whenever the corresponding control relay EHR is energized to clear signal 2, and is picked up automatically when signal 2 is put to stop by a train entering a route governed by signal 2. Relay ZAS may be picked up by putting signal 2 to stop manually, in which case its energization is delayed for a measured time interval by means of a time element relay ZTE in a well known manner. Relay 4A8 and the similar relay IGAS, associated with the high speed signals, operate in a similar manner except that a longer time interval is provided by operating the time element relay 4TE through a complete cycle by the use of an auxiliary stick relay lTES, and further, the time delay is nullified in case signal 4 or II] is manually put to stop when an approach zone in the rear of the signal is unoccupied. As will be apparent from the drawing, this is accomplished in the case of signal l by means of an approach relay QAR controlled by the track relays ZlTR and IQTR.

The approach locking relays AS control a group of section locking relays ES and WS, also shown in Fig. 1F, one relay ES or WS being provided for each direction for each detector section.

These relays function in such a manner that when a signal is cleared, a series of relays ES or WS including one for each section of the route which the signal governs will be released, these relays becoming reenergized successively when the corresponding track sections are vacated. The section locking relays ES and WS and the detector section track relays TB; control the switch locking relays LS of Fig. 10, which relays in turn govern the circuits for the switch control relays WR. in such a manner that when a signal control relay HR becomes energized to clear the signal for a route, the circuit for the control relay WR for each switch of the route is opened to electrically lock the switch in the position it then -occupies, as required for the route. As will be hereinafter explained in detail, the switch locking relays LS also control the circuits of the signal mechanisms G of Fig. 1H in such a manner that the clearing of a signal in response to the operation of its control relay HR is made dependent upon the locking of each switch of the corresponding route, while .the relays AS also control the signal circuits to provide time and approach looking for opposing signals.

One feature of my invention resides in an arrangement of the control apparatus whereby the relays are segregated in two groups in order to simplify and to reduce the cost of construc tion. One group comprises all of those relays so far described, which relays have .to do with the safety of train operation and it is to be, understood that these relays are of the standardtype generally employed in the railway signaling art. The second group of relays includes those which are used only for communication purposes such as the relays of Figs. 1A and 1B which govern the selection of routes in response topush button operation, and the indication relays which control the lamps of the operators control panel. These relays are preferably small quick acting relays of a type such as that shown in my-Patent No. 1,815,947, granted July 28, 1931, for Electrical relays, and are preferably mounted in a compact array in the control cabinet at the rear of the operators panel.

Referring now to Fig. 1G, it will be seen that the track diagram is composed of a plurality of linear units or elements eachcomprising an indicator bearing the reference K with identifying prefix. Each of these indicators is preferably arranged as disclosed in the Pelikan application hereinbefore referred to, comprising a strip of translucent material arranged to be illuminated by one or the other of a pair of lamps mounted in an enclosure at the rear of the strip. Each pair of lamps includes a white lamp, the circuit for which as already mentioned is shown in Fig. 1E, and a red lamp, as shown at the right in Fig. 1G. The approach indicators AAK and IUAK employ red lamps only.

A push button P for operating circuit controllers as shown in Figs. 1A and 1B and. containing a centrally located signal indicator GK is located at the point corresponding to the location of each signal on the track diagram. These buttons are preferably of the type disclosed in a pending application, Serial No. 128,014, filed January 29, 1937, for Circuit controllers, by W. E. Smith, but for an understanding of the present invention it will suificeto point out that each button P is biased to a mid-stroke position and has one or more normally open contacts. such as are shown for buttons 2P and 4? inFig. 1A,

which contacts become closed when the button ispushed; andalso a normally closed contact which opens when the button is pulled. The lens or bulls eye of the indicator GK in the center of the, button is arranged like the track indicators to-be illuminated by one or the other of a P of lamps mounted in an enclosure at the rear.

In normal operation, all the track switches are controlled as required to establish the different routes and the signals for the established routes are cleared solely by the operations of the buttons P for the ends of the routes, the traffic direction "which is established being dependent upon the relative order in which the buttons at the two ends of a route are operated. In systems of this character, however, it is desirable at times to operate the switches individually and for this purpose the control panel is provided with an auxiliary switch lever W for each switch or crossover, as shown. These levers are preferably of the type shown in my Patent No. 1,887,273, issued November 8, 1932, for Circuit controllers. Each lever W normally occupies a central position from which it may be moved to left or right to operate the corresponding switch control relay WR of Fig. 1G to its normal or reverse position, but the circuits are so arranged that such operation is effective only if the lever is moved when conditions are proper for operating the switch as manifested by the energization of the corresponding switch locking relay LS. Each lever W controls the white lamps of Fig. 1E, for the portions of the track diagram comprising the representation of the switch Or crossover it controls, in such a manner as to indicate the actual position of the track switch whenever the lever is moved from its center position.

The indication relays for governing the lamps of the control panel include a switch indication relay for each position of each switch or crossover, such as the relays 'INWK and IRWK of Fig. 1F, which relays, as will be clear from the drawing are repeaters of the correspondence relays INWC and 'IRWC, respectively, and also include an indication relay SP for each track section of the layout. The relay SP for each section is controlled by the section locking relays ES and WS for the same section, as shown in Fig. 1F. The route selecting apparatus controlled directly by the buttons P includes a set of route selector relays for each direction, each set including a relay for each switch section of a route. Each route selector relay has a directional designation E or W following a designation of the number and position of the track switch with which it is associated. Thus, for example, there are three route selector relays IANW, IRW and IBNW associated with crossover I and two relays 3NW and 3RW'associated with switch 3 for the direction right to left. Each route selector relay at the entrance to a route serves also as an entrance stick relay and such relays may be identified by the suffix S following the route designation. Thus associated with crossover I for the direction from left to right, the route selector relay IANES is controlled by button 2P and relays IRES and IBNES are controlled by button 4P.. In addition, an exit stick relay XS is provided for each route exit.

In the first form of my apparatus the initial operation of any route button causes the energization of a preliminary route selector for each available route for which the operated button marks the entrance end, each preliminary route -selector com rising aseries of tandem-connected relays which includes the entrance stick relay for the entrance section and a relay for the corresponding direction for each remaining section of the route, such as the relays IBNES, 3NE, BNE and YBNE for route 4I2, for example.

These relays are interlocked to prevent the energization of similar relays for conflicting routes having difierent entrance ends, and each is arranged so that it will not become energized when the corresponding switch is locked in a position which is not in accordance with the route with which the relay is identified. The energization of the last relay of each series lights the white lamp for the indicator for the exit end of the corresponding route to indicate the available exit points on the track diagram, and also marks the button for that end as an exit button, rendering the preliminary selectors it controls nonresponsive.

The subsequent operation of any button marking the exit end of a route causes the energiZation of a final route selector for that route only, each final selector comprising a series of tandemconnected relays which includes the exit stick relay controlled by the exit button and the route selector for the other direction for each remaining section, such as the relays I2XS, IBNW, 5BNW, 3NW and IBNW for route 4-I2, for example. The energization of the final selector for the selected route releases the energized reliminary selectors for the other routes having the same entrance end, the relays remaining energized comprising one for each direction for each section of the selected route. The pair of energized relays for each section such as the relays 3NE and 3NVV for switch 3 control the corresponding switch or switches as required for the route by energizing the relays WR of Fig. 1C, and also control the lighting of the corresponding portion of the track diagram.

When a route is fully established by the operation of the track switches, a representation of the complete route is displayed as a continuous illuminated strip on the track diagram, the switches are looked electrically by the operation of a signal control relay HR, Fig. 1D, and the signal at the entrance end of the route then clears automatically.

I shall now describe the operation of the first form of my apparatus under different assumed conditions, tracing the circuits in detail. I shall first assume that the apparatus is in the normal condition as shown in the drawings, and that the operator desires to clear signal 4A to pass an approaching train over route 4-I2. When the train enters section ZIT, Fig. IF, the release of track relay ZITR opens contact 9 and deenergizes the approach relay 4AR, which relay releases and closes back contact I I, Fig. 1G, to close the circuit for the red lamp of the approach indicator lAK, this portion of the track diagram of Fig. 1G being thereby illuminated to inform the operator of the approach of the train.

Normally, all the track and signal indication lamps are dark, and each button P is free to be operated to establish the entrance to a route.

To set up route 4-I2, the operator will first press button 4P momentarily. This causes the energization of the two route selector relays iRES and IBNES for the diverging routes 48 (or 4IB) and 4I2. The circuit for relay iRES may be traced in Fig. 1A from one terminal B of a suitable source of current, contact I3 of track relay 4'IR, contact I4 of button 4P,

back contact I5 of relay IRW, relay IRES, back 75 contact I5 of relay 5BNW, middle contact I! of switch lever IW, back contacts I8, 20, 22 and 23 of relays IBNW, 2X8, IANES and IRWK, front contact 25 of relay ILS to the other terminal C of the same source. The circuit for relay IBNES extends from terminal B over contact I3 of relay 4TB, contact 25 of button 4P, back contact 21 of relay IBNW, relay IBNES. back contacts 23 and 29 of relays IRW and 4X5, front contact 36 of relay INWK to terminal C. Relays IRES and IBNES upon becoming energized complete stick circuits over their contacts 3| and 32 extending to terminal B at contact I3 over the normally closed pull contact 33 of button 4P.

The operation of either of these relays lights the red lamp for indicator 4GB; to mark button 4P as an operated entrance button by closing a circuit in Fig. 1G from terminal B, back contact 34 of relay 4COS, front contact 35 of relay LRGP, contact 36 of relay IRES or contact 31 of relay IBNES, through the red lamp of indicator 46K to terminal C.

Relay IRES upon becoming energized completes a circuit from terminal B at its contact 38, Fig. 113, over back contacts 39 and 40 of relays 8XS and 5ANES through relay 5ANE, back contact 4| of relay 5RW, middle contact 42 of lever 5W, front contact 43 of relay 5NWK to terminal C. Relay 5ANE picks up and completes a circuit from terminal B at back contact 44 of relay 5ANWS, contact 45 of relay 5ANE through relay IANE, contacts 46 and 41 of relay 'IRWS, contact 48 of relay IZXS, contact 49 of lever 1W, contact 59 of relay 'INWK to terminal C.

At the same time, the energization of relay IBNES completes a circuit from terminal B at its contact 5!, Fig. 1A, for relay 3NE, which circuit extends over back contacts of the conflicting relays 6X8 and 3RES to terminal C at a front contact of relay 3NWK. Relay 3NE picks up and closes its contacts 52 and 53, Fig. 13, to connect terminal B to the circuits for relays 5BNE and 5RE. The circuit for relay 5BNE is completed to terminal C at front contact 43 of relay 5NWK and relay 5BNE picks up but relay 5RE is prevented from picking up because its circuit is now open at back contact 54 of the conflicting relay 5ANE. Relay 5BNE upon picking up connects terminal B at contact 55 to the circuit for relay IBNE, which circuit is completed to terminal 0 at contact 50 of relay 'IN'WK so that relay 'IBNE picks up and by opening contact 56 in the circuit for the conflicting relay IRE prevents that relay from picking up in response to the energization of relay 5ANE.

It will be seen therefore that the operation of button 4P causes the energization of the preliminary selector for route 4!ll comprising the relays IRES, 5ANE and IANE, and that for route 4I2 comprising the relays IBNES, 3NE, 5BNE and IBNE. The circuits for the conflicting relays 5RE and IRE have been opened, as above described, and in addition, the circuit for relay IANES which conflicts with relay IRES has been opened at contact 51 of relay IRES, Fig. 1A, and the circuit'for relay 3RES which conflicts with relay 3NE has been opened at contact 58 of relay 3NE.

The energized relays IRES, 'lANE and IBNE, by closing contacts 59, 60 and GI, respectively, in Fig. 1E, cause the white lamps for the exit section indicators IK, IUK and IZK, respectively, of the track diagram, to be lighted to thereby indicate the available exits for the routes governed by signal 4. This informs the operator that each of the buttons 8P, HIP and I2P has been marked as an exit button and now controls an exit relay instead of an entrance relay. Button 8P normally controls an entrance stick relay EANES over its contact 62, Fig. 1B, but this circuit is now open at contact 63 of relay ANE and a circuit for the exit relay SXR has been prepared from terminal B at contact 38 of relay IRES over contact 64 of button 8P, contact 55 of relay 8X5, relay BXR, contact 56 of relay EANW. to terminal 0. The operation of contacts 67 and 68 of relays IANE and IBNE places the exit stick relays IIiXS and I2XS under the control of buttons IUP and I2P, respectively, in place of relays lANWS and IBNWS. Relay 'IRWS has been rendered nonresponsive to the operation of button I2P by the opening of contact 56 of relay 'IBNE.

The operator now completes the selection of the desired route by momentarily operating the corresponding exit button. Since route 4-I2 is to be selected, he will operate button I2P, completing the circuit for relay IZXS from terminal B, contact 59 of relay lTR, contact of button I21 front contact 68 of relaylBNE, back contacts TI and 72 of relays 'IRWS and 'IBNWS, relay IZXS to terminal C. Relay IZXS picks up and completes a stick circuit over its contact 13 and back contact 14 of relay "IRE, which extends to terminal B at contact 55 of relay 5BNE.

Relay I2XS upon becoming energized causes the'successive energization of relays 5BNW, 3NW and IBNW, these relays together with relay I2XS comprising the final selector for route 4-I2. The circuits for these relays are generally similar to the selector circuits previously traced, the circuit for relay 5BNW including front contacts I5 and 16 of relays IZXS and TBNE, and the circuits for relays 3NW and IBNW including front con-' tacts ll and i9, Fig. 1A, of relays 5BNW and. SNW, respectively. Relay 5BNW also closes contact I8 in the'circuit for relay 3RW but that relay does not pick up because its circuit includes contact 58 of relay 3NE which is now open.

Relay IBNW upon becoming energized opens contact IS in the circuit for relay IRES and since contact 89 of relay IBNES bridging contact I8 is also open, relay IRES releases and consequently relays 5ANE- and 'IANE release, extinguishing the white lamps for indicators IK and IOK and reconditioning buttons ti? and IUP and also 2P as entrance buttons, so that these buttons may now be operated to establish a parallel route -'-8 or 4-45. Button 6P, which controls a conflicting route, remains nonoperative. Relay IBNW by closing contact BI, Fig. 1E,

of the switch sections 'IBNK, 5BNK, 3NK and iBNK of Fig. 1E become lighted as soon as the selection of the corresponding route portion is completed, that is, upon the closing of contacts 82, 84, 86 and 88, Fig. 16, of relays IZXS, 5BNW, 3NW and IBNW, respectively, since contacts 83, 85, 81 and 89 of relays 'FBNE, 5BNE, 3NE. and IBNES are also closed.

completes a circuit in Fig. 1D to energize the signal control relay II-IR, which circuit may be traced from terminal B over back contacts 90 and 9| of relays 'IBNWS and. 'IRWS, front contacts 92, 93 and 94 of relays 'IBNE, 'INWK and BNWK, front contacts, 95, 96, 91 and 98 of relays SNWK, INWK, iBNW and IBNES, relay 4HR to terminal C.

My apparatus is so arranged that the clearing of a signal in response to the operation of its control relay is made dependent upon the looking of each switch of the route which such signal governs, as described in the Allen and Thompson application hereinbefore referred to. The initial result of the operation of relay IHR is to open back contact 99, Fig. 1F, in the circuit for relay 4AS, which relay therefore releases and opens its contact I00 to release the section looking relay 4ES. Relay ms in turn opens contact IUI to release relay 3ES. Relay 3E8 upon releasing, opens contacts Ifl2 and I03 in the circuits for relays 5ES and IE8, releasing relay IES. Relay5ES, Which is associated with a section 5T not included in route 4I2, is not released because contact Iii2 'is bridged by the closed contact I64 of relay SNCR. Relay 4A8, by closing back contact I05, Fig. 1H, prepares a circuit over contacts I06 and IE1 of relay il-IR, for the signal mechanism GAG.

Relays 4ES, 3E8 and IE8, by closing their respective back contacts I83, H39 and Ill), Fig. 1F,

' route is fully established.

At the same time, contacts IHI and H5, Fig. 10, of relays 4E3 and IES open to release the switch locking relays ILS and ILS, respectively, and relay 3E3 opens its contacts H6 and II! to release relays BLS and 5LS, thereby electrically locking the switches by opening the circuit for Relay IBNW upon becoming energized also each of the polar stickrelays WR. The closing of the back contacts of the LS relays completes the, signal circuit, which may be traced in Fig.

- 1H from terminal B, contact II8 of relay IZAS,

contact II9 of relay INCR, back contacts I20 and I2I of relays 'ILS and 5L8, contact I22 of relay 5NCR, back contact I23 of relay 3L8, contact I24 of relay '3NCR, back contact I25 of relay ILS, contact I26 of relay INCR, back contact I05 of relay IAS, contact I06 of relay IHR, normal polar contacts I21, I28, I29 and I35, relays IWP, 3WP, 5WP and 'IWP, contacts I3I, I32 and I33 of thetrack relays ITR, 3TR and GTR, thence over the pole-changer contacts I34 and I35 of the line relay 4DR through the winding of mechanism IAG to terminal C at contact I01 of relay II-IR.

Signal 4A now clears and relay IRGP releases in responseto the opening of back contact I36 of mechanism 4AG, and at its contact 35, Fig. 1G,. relay 4RGP controls the circuits for indicator 4GK to cause the indication displayed by the lens in button 4P to change from red to green.

If new the approaching train enters the first detector section 4T of the route, relay 4TB, will release and by opening contact I3, Fig. 1A, will cause relay IBN ES and consequently all the route selector relays for route 4-I-2 to release, and relay IBNES will release relay 4HR. Mechanism 4AG releases in response to the openingof contact I33 of relay 4TB. and its circuit is also opened'at contacts m6 and It! of relay 4HR. Relay 4RG-P now picks up, and by opening its back contact 35, causes indicator 4GK to become dark. Relay 4RGP also completes a pick-up circuit for relay 4A8 which may be traced in Fig. 1F from terminal B, back contact I31 of mechanism 19G for the distant signal I9, contacts 99 and I33 of relays 4l-l-R and 4RGP, back contact 13-9 of the slow acting repeater 4T]? of the-track relay for section 4T through relay 4A8 to terminal C. Relay IlAS therefore picks up'and completes its stick circuit at contact I40. Relay 4A5 also closes contact I05, Fig. 1F, in the circuit for relay 4E3, which relay however, does not pick up until section 4T is vacated to close contact I SI of relay 4'-I- R. It follows therefore that relays 48F, 38F and 'I SP are held energized by relay 4TB, as long as section 4T is occupied. Relay ATP by opening its front contact I42, Fig. 1E, extinguishes the white lamps for the indicators 4K, IBNK and B'IK and by closing its backcontact I43,"Fig. 1G, lights the corresponding red. lamps for these indicators as long as section 4T remains occupied.

Since contacts such as 86 and 81 of relays SNW and SNE in the circuits for the white lamps for the indicators for route 4-I2 are now bridged by contacts of the corresponding SP relays such as contact I44 of relay 3SP, it is apparent that the white lamps for the unoccupied sections in advance of the train will be maintained lighted by the relays SP until these sections become occupied, the indicators for the sections becoming red successively in response to the release of relays 3T1? and 'I-TP, and then becoming dark as these relays pick up when the train vacates the corresponding sections. Thus when section 4T is vacated, relay 4TB, picks up closing contact I41 to energize relay 4ES, thereby'releasing relay 48?, which is quick acting, and opening contacts such as III in the circuits for the white lamps for the indicators for section 41, before the slow acting relay 4TP controlled by relay 4TB has closed its front contact I42 in these circuits. Relay '3ES does not pick up as long as contact I45 of relay 3TB. remains open and consequently relays SSP and 16? are held energized by relay STR as long as section 3T is occupied, and similarly, relay 'ISP is held energized by relay 'ITR. as long as section "IT is occupied.

One advantage of this arrangement is that it provides a distinctive approach locked indication of the track switches. Assume, for example, that route 4-I2 is cancelled manually by pulling button 4P to open contact 33 in the stick circuit for relay IBNES momentarily, before the train enters the route. This willrelease the route selector relays and cause indicator 4GK to become dark, but if the approach zone is occupied, relay 4AR will be in its released position and the reenergization of relay 4As will be delayed until the time element measured by relays 4TE and 4TES is completed. Conse quentlyfthie relays S? will remain energized and the White lights for the locked route will not be extinguished until the time element is completed, this indication being distinctive because the indicators GK for both ends of the route are dark. It is also evident that if the section locking relay ES or WS for any section fails to pick up-after a train passes through the section, the white lamps for the section will become lighted as soon-as the section is vacated to indicate that condition. It follows that the normally dark condition of the panel indicates thatthese relays are properly energized.

-I shall next assume that with the apparatus in the normal condition as shown that buttons 4P and I2P are operated in the reverse order, button I2P being operated first so as to set up route I2-4 for a train movement from right to left.

In response to the operation of the entrance button I2P, Fig. 13, a circuit is closed over its contact is and back contact 63 of relay 'IBNE to pick up relay 'I-BNWS, and another circuit is closed over its contact I46 and back contact I4'I of relay IRE to pick up relay "IRWS, and these relays complete stick circuits at contacts I48 and I49 extending to terminal B over the closed contact 1-59 of button Ii-P and contact 69 of relay 'ITR.

Relay IBNWS, by closing contact I5I, picks up relay 5BNW and at the same time relay "FRWS closes contacts I52 and I53 to pick up relays 5ANW and 5RW. The circuit for relay 5ANW includes back contact I54 of relay 5ANE and is completed to terminal C at contact 43 of relay 5NWK while that for relay 5RWextends to terminal C at contact I55 of relay 5LS, and while both relays are energized momentarily only relay 5ANW will remain energized, the circuit for relay 5RW being opened at back contact I55 of relay 5BNW. Relay 5RW has a corresponding back contact M in the circuit for relay 5BNW, but if this contact opens momentarily, it is without effect because contact 4| is now bridged by the closed back contact I51 of relay 5RE.

Relay 5BNW by closing contacts Hand I8, Fig. 1A, picks up relays SNW and 33W, and relay 5ANWby closing contacts I58 and I59, picks up relays IANW and IRW.

Relay 3NW energizes relay IBNW over the circuit which extends from terminal B at contact IQ of relay 3N-W through relay 3BNW, contacts I60 and 29 of relaysBBNW and 4XS, contact 3B of relay INWK to terminal C. Relay IBNW picks up and by opening itscontact I6I, bridging contact I6 of relay 5BNW which is now open, releases relay IRW.

Three preliminary route selectors are now energized; one for route I22 comprising relays 'IRWS '5ANW and I'ANW, one for route I2-4 comprising relays 'IBNWS, 5BNW, 3NW and IBNW, and one for route I26' comprising relays IBNWS, 5BNW and 3RW, the white lamps of the corresponding exit indicators 2K, 4K and IiKbeing lighted by the closing of contacts I62, BI and 22'! of relays IANW, IBNW and 3RVV.

The conflicting route buttons BF and I0 have been rendered nonoperative by the opening of contacts 66 and I64 of relay 5ANW and by the opening of contact 4% of relay 'IRWS, respectively.

Buttons 2P, 4P and 6? have been conditioned as exit buttons and now control their respective exit relays ZXS, 4XS- and 6X8. Since route I2-4 is to be selected, the operator nowoperates button 4P completing the circuit for relays 4X8 from terminal Bat contact I3 of relay. 4TB, contact 26 of button 4P, frontcontact 2.1: of relay IBNTW, backcontacts I55 and I66 of relays IRESand.

IBNES, relay 4X3 to terminal C, and relay 4X8.

picks up completing a stick circuit at its con-tact I63 extending to terminal B at contact I9;of, relay 3NW.

Relay 4X8 upon picking up, closes its contacts I61 and I68 and energizes the final selector for route I2-4. Contact I61, Fig. 1B, is in series with the open back contact I69 of relay IBNW and is therefore ineffective, but contact I68, Fig. 1A, which is in series with the front contact Ill] of relay IBNW completes the circuit for relay 3NE which picks up and closes contacts 52 and 53. Contact 53 is not effective to pick up relay ERE because the circuit is now open at contact I56 of relay EBNW, but relay EBNE picks up in response to the closing of contact 52 and in turn closes its contact 55 to pick up relay IBNE, and the latter relay by closing its con tact 6| lights the entrance indicator I2K, thereby completing the selection for route I24.

When relay 3NE picked up it released relay 3RW by opening its back contact 58, and when relay 'IBNE picked up it opened the. circuit for relay 'IRWS at contact 56, thereby releasing relays IRWS, 5ANW and IANW and extinguishing the 'White lights for sections 6K and 2K. The remaining operations are similar to those already described, except that relay IZHR will become energized in place of relay AI-IR. and signal I2 will clear in place of signal 4A.

Returning now to a consideration of route 4I2, I shall assume that the operator desires to clear the call-on signal 40 to admit a second train to section 4T while that section is occupied by a first train moving from left to right. A connection to terminal B for picking up relay IBNES becomes available at back contact III of relay 4TP shortly after relay 4TR releases, and it follows that the route may be set up again by operating buttons lP and IZP as previously described. Relay iHR will pick up, but mechanism 4AG will remain deenergized because itscircuit is open at contact I33 of relay dTR and indicator GGK will continue to display a red light after the exit button I2? is operated.

To clear signal 40 for route 4I2, the operator will again press button il? after he has picked up relay lHR as above described, the operation of button 4P in this case completing a pick-up circuit for relay ACOS from terminal B, contact I'II of relay 4T1, contact 26 of button 4P, front contact 21 of relay IBNW, back contact I65 of relay IRES, front contact I66 of relayIBNES, contacts I72 and I73 of relays lRGP and IHR, relay 4008 to terminal C, and relay 4008 will pick up to complete a stick circuit over contact I I3 and its own contact I14 which extends to terminal B over contact I3 of relay ITR or contact I'II of relay 4TP.

' Relay 4CO-S completes a, circuit in Fig. 1H for mechanism 40G which is a branchof the circuit for mechanism 4AG already described extending from terminal B at contact II8 of relay I2AS to contact I66 of relay 4HR and thence over contact ill: of relay 4008, contact I16 of mechanism 4AG, the winding ofmechanism 4CG,

. contact IIll of relay IHR to terminalC.

Signal 40 now clears, relay 4RGP releasing due.

to the opening of contact I'I'I of mechanism 40G.

When relay ICOS picked up, it caused indicator IGK to display a distinctive flashing red indication by closing its front contact 34, Fig. 1G, which is connected to terminal B over contact I18 of a continuously operating flasher relay CD. When signal 40 clears, indicator IGK will display a continuous flashing greenindication due to the closing of .back contact 35 of relay IIRGP.

Since relay- IBNES is now energized over back contact III of relay 4TP, it will not release if the second train enters section 4T before the first train vacates that section. In this case, the operator will cancel the route manually by pulling the button 4P to open the stick circuit for relay IBNES.

I shall next assume that with the apparatus in thanormal condition, as shown, that the operator presses buttons 4P and 8? in that order to establish route 48. The result of pressing button 4P under this condition has already been described. When button 8P is operated, the pick-up circuit in Fig. 13 already traced for relay SXR will become closed at contact 6%, relay 8XR Will pick up and will prepare a circuit for relay 8XS extending from terminal B at contact 38 of relay IRES, contact I79 of relay 8XR, through relays 8XS and BXR, contact $5 of relay 5ANW to terminal C, but relay BXS does not pick up at this time because it is short circuited by a connection to terminal B at contact 33 over contacts 64 and 65. When button SP is released, however, relay 8X8 picks up in series with relay 6% and maintains both relays energized.

Relay 8X8 upon picking up closes contacts 585 and I8I, Fig. 1A, in the circuits for relays IANW and IRW. The circuit for relay IANW is open at contact 5'Iof relay IRES and only relay IRW picks up, lighting the entrance indicator lK by closing its contact I82, Fig. 1E. By opening its back contact 28, Fig. 1A, relay IRW releases relays IBNES, 3NE, SBNE and 'lBNE, thereby reconditioning buttons GP and I2P as entrance buttons and causing indicator I2K to become dark. Relay, BXS, by opening contact 39, releases relays 5ANE and 'IANE, reconditioning buttons 8? and IOP as entrance buttons and causing indicator IIlK to become dark.

In Fig. 1C, relay I RW completes a circuit from terminal B at contact I 83 of relay ILS through the right-hand winding of relay IWR, contacts I84, I85 and I86 of relays ILS, IRW and IRES to terminal C. Relay IWR is a stick polar relay arranged to remain in its last operated position when deenergized and it now reverses, closing its right-hand contacts to operate switches IA and IE to reverse, at the same time releasing relays INWC and INWKLwhich are controlled in the same manner as the corresponding relays for crossover 1 shown in Fig. 1F. Relay INWK by closing contact I81, Fig. 1G, completes a circuit over back contact :88 of relay IRWK for the red lamp for the diagonal indicator IRK. Since the white lamps for'indicators IK and 4K are now lighted due to the closing of contacts 59 and 582 of relays IRES and IRW, respectively, a distinctive indication is provided on the track diagram indicating that switches IA and IB are unlocked or in transit.

It will also be seen that since the circuit for the red lamp I RK over back contacts I8! and I 88 is independent of the route control, a distinctive indication will be displayed in the event a track switch becomes displaced at any time from its proper, normal or reverse position, so that the operator may promptly take the proper action to correct the defect.

When switches I complete their movement and become locked reverse, relay IWP becomes energized in the reverse direction and relays IRWC and IRWP pick up. Relay IRWKopens the circuit for the red lamp for indicator IRK and at contact I89, Fig. 1E, completes a circuit over contacts I 99 and I9I of relays IRW and 8X8 for the white lamp of indicator IRK. The white lamps for indicators K, IRK and IX are now lighted, indicating that route 4-8 is fully established.

Relay iHR now becomes energized over a circuit in Fig. ID from terminal B, contacts I92, I93, I94 and I95 of relays 8X8, IRWK, IRW and IRES, relay 4BR to terminal C. Relay AHR picks up, releasing relay 4A8 by opening contact 99, and relay iAS releases relay 4E8 by opening contact I99, but relay BES does not release as previously described, contact IIlI of relay 4ES in its circuit being now bridged by the closed contact I96 of relay I RCR. Relay iLS is released by the opening of contact IE4 of relay 4E8 but it is the only switch locking relay released and upon the closing of the back contact 292 of this relay a circuit is completed for mechanism ICG which may be traced in Fig. 1H from terminal B at contact I98 of relay IWS, over contact I99 of relay 4HR, back contacts 200, 20I and 292 of relays INCR, ZHR and ILS, contact 203 of relay IRCR, back contact I05 of relay IAS, contact I06 of relay II-IR, reverse contact IZ'I of relay IWP, contact I'I6 of mechanism 4AG, the winding of mechanism 40G, contact ID! of relay AHR to terminal C, Signal 4C will therefore clear and indicator 4GK will change from red to green as in the case previously described.

It will be noted that the circuit just traced is connected to terminal B over contact I 98 of relay 5WS. This relay is controlled by relay IQAS as shown in Fig. 1F and contact I 98 therefore functions like contact II8 of relay IZAS in the circuit for mechanism SAG to provide time locking of opposing signals.

By referring to Figs. 1E and 1G it will be seen that when the train enters route 4-8, the white lamps for indicators 4K and IRK will be extinguished and the red lamps lighted by the operation of contacts I 52 and 284 of relay ATP, indicator IK also becoming red due to the closing of contact 205 of relay ITP when the train enters section IT. Indicator 4K becomes dark when the train vacates section 4T but the red lamp for indicator IRK is maintained lighted over contact 206 of relay ITP until the locking of switches I is released as the train vacates section IT. This arrangement has the advantage that it warns the operator that route 4--I2, for example, although unoccupied, cannot be set up because switch IB is locked reverse by a train occupying section IT.

I shall next assume that after having set up route 4-8 as above described, the operator pushes buttons SP and IIIP to set up route 8-Ill.

Button 8P serves as an entrance button as lon as relay 5ANE is deenergized, that is, not only when no button such as AP in the rear has been operated, but also following the release of relay 5ANE after button 8? has been operated as an exit button. In th present case, button BP is operated again after route 4--8 has been set up as above described, and the closing of its contact 52 completes the circuit for relay 5ANES, which relay upon picking up closes contact 49 to pick up relay 5ANE, and the latter relay closes contacts 45 and 291 to pick up relays 'IANE and IRE. The white lamps for the exit indicators IOK and I2K become lighted due to the closing of contacts -69 and 298 of relays IANE and IRE, marking buttons It? and IZP as exit buttons.

Button IDP is now operated, completing a circuit from terminal B at contact 209 of relay 5'I'R, contact 2I0 of button IIiP, front contact 61 of relay IIIXS to terminal C. Relay IBXS picks up, closing contact 2I2 to complete its stick circuit extending to terminal B over contacts 44 and 45 of relays SANWS and EANE. Relay IGXS at contact 2I3 connects terminal B to a circuit, one branch of which extends over front contacts 2 i4 and I54 of relays 'IANE and SANE through relay 5ANWS to terminal C at contact 43 of relay SNWK. Another branch of this circuit extends over front contact 2I5 of relay 'IANE through relay 5RW, but this branch is open at contact 54 of relay 5ANE. Relay EANWS picks up and at contact 2I6 closes its stick circuit extending to terminal B over contacts 2M and 2I3. Relay IOXS opens its back contact 2 I1, thereby releasing relay IRE and extinguishing the white lamp for indicator I2K. This completes the route s lection, and since the remaining operations involved in the clearing of signal 8 are similar to those previously described, a detailed explanation is believed to be unnecessary.

It has already been explained that when the entrance button AP is operated, both buttons SP and IIIP become exit buttons. A feature of my invention is the provision of through routing past intermediate signals, the apparatus being so arranged that if buttons 4P and I9P are operated in that order, the two routes I8 and 8I 6 Will become established without operating button 0 BP, precisely as if button 8P were operated twice in succession prior to the operation of button IilP as above described.

Assuming that with the apparatus in its normal condition as shown, that button 4P is operated. The preliminary selector comprising relays IRES, BANE and 'IANE will become energized and if button IQP is operated while relay 'IANE is energized, relays IRXS and 5ANWS Will become energized as already described. Button 8P not having been operated, relay 5ANWS upon relay 'IANE, back contact 2 of relay IANWS,

becoming energized completes a pick-up circuit for relay BXR which may be traced from terminal B, contact 38 of relay IRES, contacts M8 and 2I9 of relays 5ANES and SANWS, contact 55 of relay 8X8, relay BXR, contact (it of relay EANW to terminal C. Relay 8XR picks up and completes a pick-up circuit for relay 5ANES from terminal B at contact 289 of relay 5TR, contacts 220 and 22I of relays 5ANWS and BXR, through relay SANES to terminal C at contact 43 of relay ENWK. Relay 5ANES picks up, closing its stick circuit at contact 222, and by opening contact 2I8 causes relay 8X8 to pick up in series with relay BXR, and relay 8XS closes contact I 8I to pick up relay IRW, thereby completing the selection of the through route 4Iil.

It will be seen that when a train passes signal 40 to enter route 4I0, relays IRES, SXR, 8X5 and IRW will be released by the opening of contact I3 of relay ITR without effect upon the relays SANES, etc. for route 8-I0, the latter relays being released when the train passes signal 8, by the opening of contact 209 of relay 5TR.

I shall next assume that the apparatus is in the normal condition as shown and that buttons Il'lP and 4P are operated in that order to set up route III4. The'operation of button [9P picks up relay 'IANWS over back contact 61 of relay TANE and relay ,IANWS closes contacts 223 and 224 in the circuits for relays 5ANW and 5RW. Relays '5ANW and 5RW pick up, relay 5ANW opening contacts 66 and I 54 to render relays 8XR, 8X8, 5ANES and 5ANWS nonresponsive, and closing contacts I59 and I59, Fig. 1A, in the circuits for relays IANW and IRW. Relays IANW and IRW pick up-and light the white lamps for the exit indicators 2K and 4K. Relay SRW closes contacts 225 and 225m the circuits for relays 3NW and 3RW. Relays SNW and 3RW pick up, relay 3NW closing contact It in the circuit for IBNW but this relay does not pick up because its circuit is open at contact 23 of relay IRW. Relay SRW closes contact 22? li hting the white lamp for the exit indicator 6K.

Assuming that the exit button 4? is now operated, relay 4X8 is picked up over front contact 15 of relay IRW, closing contact It? to pick up relay EANE, and relay EANE closes contact 45 to pick up relay TANE. When relay 4X8 picks up, the opening of its back contact 29 releases relay IAN'W, since contact 228 of relay IRW is now open. When relay EANE picks up, the opening of its backcontact 54 releases relays ERW and consequently relays SNW and 3RW release. This completes the selection for route le l. It will be noted that relay 5ANWS is operated only when a route for traific moving from left to right is being set up, and that relay EANW is operated only when a route from right to left is being set up. These relays are interlocked, the circuit for each relay including a back contact of the other and serve as directional stick relays to properly govern the apparatus associated with the intermediate button 8P when the trailic direction is determined by the relative order of operation of buttons at other locations.

An important feature of my invention is the provision of means for insuring proper operation when the track layout provides a plurality of alternative routes between the same route ends, there being a number of such situations in the layout chosen, as is obvious from the drawings. Considering the two routes ll-59 for example, route 4Hl over i reverse is chosen as the preferred route over, the one including 5 reversed because it frees a parallel route 6i2. This choice is eiiected in a very simple manner by merely omitting one of the cross checks for the route selector relays which are ordinarily provided when no alternatives exist. ple, in the case of routes 4-12 and 6l2, it will be seen that the corresponding relays tNE and 3RES are fully cross checked, the circuit for each relay including a back contact of the other. In

the case of the alternative routes 4-lii over r1 5 normal and '5 reversed, the circuit for relay ERE includes back contact 54 of relay 5ANE, but there is nothing to prevent the energization of relay EANE ii terminal'B is connected to both relays at the same time, the back contact I51 of relay fiRE in the circuit for relay EANE being bridged by back contact 4| of relay ERW, consequently onlythe route 4l0 over 5 normal becomes established when both are available. If for any reason relay EANE is prevented from picking up, as would be the case for example, if switches l were locked normal by a train occupying section 5T, relays IBNES, 3NE, 5123 and LANE would pick up in response to the operation of the entrance button 4P, but relay IRES would be prevented from picking up because its circuit would be open at contact 25 of relay ELS, this relay occupying its released position when section IT is occupied. The operation of the exit button WP would then pick up relays lilXS, SRVV,

3NW and ilBNW to complete the selection for the secondary route 4-H! over 5 reversed. When relays ERE and ERW are both energized, the circuits for relays EBNE, SBNW, BANE, EANES, 5ANW and EANWS are open at contacts For examiii) My apparatus is also arranged so that any secondary route may be-selected at will by the' operator by the operation of one or more of the individual switch levers W which define suchroute. This is accomplished by including contacts of the levers W at the proper points in the route selector relay circuits. For example, as-

sume that switch 1 remains reversed and doesnot respond to the operation of buttons 4? and E2]? to establish route 4i2 over 1 normal. The operator after cancelling the set up by-pulling button dP momentarily will reverse lever 7W to agree with the position of the crossover land will then reoperate the entrance button 4?. In

this case, relays lRES, EANE and IRE will become energized, and also relays EBNES and 3NE, but the circuit for relay TBNE is open at contact 59 of lever 1W, Fig. 1B, which contact now occupies its right-hand position. The operation of the exit button HEP will then cause relays l2XS, ERR/V and IRW to pick up, relay iRW releasing relays IBNES and SNE, thereby completing the selection of the run-around route 4l2 over I and 1 reversed. Similarly, the secondary run-aroundroute dl2 over 5 and 1' reversed may be selected by reversing both levers 5W and TW, and the secondary route il0 or lfi4 over 5 reversed maybe selected by reversing lever 5W or 1W respectively. In no case however, can a route set up be interfered with by an inadvertent movement of a switch lever after the route is established. In the case described involving lever 1W, for example, it will be apparent that since contact 229 of relay IRE is open, the circuits for the conflicting route selectors IBNE, etc. are held open at back contact A? or Q8 of relay IRWS or IZXS, if lever 7W is moved to close contact 49 after the route is established. On the other hand, when a route including crossover 1 in its normal position is set up, relay EANE or 'IBNE will bee'ne'rgized to close contact 238 or 23L and in this case'the opening of contact 59 as the result of an inadverte-nt movement of lever IV] to reverse is without effect. Furthermore, relay 'IWR. is nonresponsive to the operation of lever 'lW after a route is established because relay ILS is then released.

The arrangements for operating the track switches individually will be readily apparent from a consideration of Fig. 10. For example, if

lever IV!" is moved to the left or right while relay lLS is energized, a circuit is completed from terminal B, contact I83 of relay ILS, through the left-hand or right-hand winding of relay IWR, contact 232 or I84 of relay LS over the left-hand or right-hand contact 233 of lever W to terminal 0, to operate the contacts of relay EWR, to a position to correspond with that of the lever contact. In systems employing individual switch levers it is desirable to arrange the levers so they are ineffective unless oper-' -ated while the switch locking is released. This 4| and 15! of relays 53E and ERW so that the secondary route when established is isolatedand For the oppois accomplished in a novel manner in the present system by providing each lever W with a center contact which must be closed in order to effect the energization of the associated locking relay LS. Thus relay I LS has a pick-up circuit which extends from terminal B at contact Il l of relay 4E5 over front contacts of the locking and track relays for sections IT and 4T, through the winding of relay ILS, contact 233 to terminal C, the lever contact 233 being bridged by a front contact of relay lLS when that relay becomes energized.

Since switches I will remain locked unless iW is restored to its center position and the operator may fail to note an inadvertent displacement of a switch lever from that position, it is desirable to indicate such displacement on the track diagram and to also distinctively indicate the operation of the track switch when it is operated individually by the corresponding lever W. This is accomplished in a novel manner by providing normal and reverse contacts of each lever, such as contacts 224, 225 and 226 of lever IW, in the circuits for the white lamps for each of the indicating sections for the corresponding switch, as shown for sections IANK, I RK and I BNK in Fig. 1E, for example. It will be apparent that whenever lever I W is moved to left or right, the white lamps IANK and IBNK will become lighted over circuits including contacts 224 and 225 of lever IV? and contacts 22'! and 223 of relay INWK, respectively, or lamp IRK will become lighted over contact 225 of lever IV] and Contact I89 of relay IRWK, depending upon the actual position of the track switch, irrespective of whether lever IW occupies its left-hand or righthand position. If the switch responds to the lever operation, the lamp which became lighted as a result of the lever movement, becomes dark, but then the red lamp for indicator I RK becomes lighted over the circuit of Fig. 1G including back contacts I81 and I88 of the switch indication relays to display the transit indication, and the white lamp for the position to which the switch is operated becomes lighted when the switch completes its operation. On the other hand, if the switchfails to respond to the lever movement because it is locked or because it already occupies the required position, the lamp which became lighted as the result of lever movement remains lighted. It follows that the normal dark condi tion of the indicators is obtained only when lever IW is in its center position, and that th arrangement indicates individual switch lever operation in a distinctive manner and also gives the operatorv full information as to how the switch responds to such operation.

The second form of my invention as disclosed in Figs. 2A. to 2E, inclusive, differs principally from the first form in the employment of a different arrangement of route selector circuits. In the. second form a pair of route relays NR and RR is provided for each single switch and three route relays ANR, RR and BNR for each crossover. The exit relays XS are not required, except for the intermediate signal 8, and the route selector relays are employed in only one direction at a time.

To explain the second form of the apparatus, I shall first assume that the apparatus is in the normal condition as shown and that the operator desires to clear signal 5A.

To set up route 4--I2, the operator will operate buttons AP and IZP as previously described. The operation of button 4? of Fig. 2A completes circuits over contacts I3, I I' and 26 to pick up relays IRES and IBNES, energizing the preliminary selectors for routes 4Ii) and 4I-2 and lighting the exit lamps precisely as described in connection with the first form of the apparatus.

Likewise, relays 3NE, SANE and 'IBNE at contacts 58, 54 and 55 open the circuits for the confiicting relays SRES, 5RE and IRE in Figs. 2A and 2B.

When the exit button IEP is operated, a circuit is closed from terminal B at contact 69 of relay 'ITR over its contact Id and front contact 68 of relay 'IBNE to energize the route relay IBNR, which relay picks up and closes a stick circuit over its contact 229 extending to terminal B over contact 238 of relay 'IBNE, and also closes contact 23I, Fig. 2A, to pick up the route relay 3NR over a circuit including contact 232 of relay SNE. Relay SNR upon becoming energized, closes contact 233 to pick up the route relay IBNR over a circuit including contact 234 of relay IBNES. Relays 'IBNR, EBNR, 3NR and. IBNR open their respective back contacts 235, 236, 231 and 238 in the circuits for the corresponding RE and RW relays, thereby isolating the route circuits for route 4I2. The opening of contact 233 of relay iBNR releases relay IRES and the remaining energized route selector relays associated with the diverging routes 48 and 4I 0.

Assuming the switches to be already in the position required for route 4I2, as shown, the operation of the route relays completes a circuit for relay dI-IR which may be traced in Fig. 21) from terminal B at back contact 93 of relay TBNES and front contacts of the route relay NR and the corresponding indication relay NWK for each switch of the route, thence over front contact 98 of relay IBNES through relay 4H3 to terminal C. Relay ll-IR becomes energized and affects the clearing of signal 4A as explained in connection with Figs. 1F and 1H in the description of the first form of the apparatus.

In Figs. 20 and 2E only a portion of the circuits are shown, these being generally similar to the circuits of Figs. 10 and 1E already described, differing therefrom only in that each pair of route selector relay contacts which is closed in Fig. 1G to complete the selection of a route portion, such as contacts I and I86 of relays IRW and IRES, is replaced in Fig. 20 by a single route relay contact, such as contact 239 of relay IRR, having the corresponding function. Similarly, each pair of contacts such as contacts 83 and 89 of relays IBNW and IBNES for completing the circuit for the White lamp of indicator I BNK in Fig. IE is replaced in Fig. 2E by a single contact such as contact 240 of relay IBNR. The operation of relays WR by the circuits of Fig. 2C and the lighting of the track diagram lamps is effected in the same manner in the second form of the apparatus as already described.

I shall next assumethat with the apparatus of the second form of my invention in the normal condition as shown that buttons IZP and 4P are operated in that order to set up route I24. Button I2P when operated completes the circuits for relays IBNWS and IRWS at contacts I9 and lit to energize the preliminary selectors for routes I22, I24 and I2-6 and to light the exit indicators 2K, 4K and 6K, as explained in the description of the first form of the apparatus.

When the exit button 4? is operated, a circuit is completed at contact 25 over front contact 21 of relay IBNW to energize relay IBNR., which 

